From mboxrd@z Thu Jan  1 00:00:00 1970
From: will.deacon@arm.com (Will Deacon)
Date: Fri, 21 Oct 2011 09:46:41 +0100
Subject: Possible regression in kexec on ARM ARMv6 and ARMv7 cores
In-Reply-To: <20111021083426.GA16088@verge.net.au>
References: <20111020042444.GA20260@verge.net.au>
	<20111020070105.GA28548@mudshark.cambridge.arm.com>
	<20111020080823.GA2716@verge.net.au>
	<20111021083426.GA16088@verge.net.au>
Message-ID: <20111021084641.GA30168@mudshark.cambridge.arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Fri, Oct 21, 2011 at 09:34:26AM +0100, Simon Horman wrote:
> I have tested the kexec/mmu-off branch of your tree on the UP board
> I mentioned above and kexec works :)

Hurrah! Thanks for giving it a spin.

> > You mention UP in particular, which I will test.
> > Do you have any thoughts on SMP?

Yes. Currently [i.e. on my branch above] you can do SMP kexec using the CPU
hotplug platform_cpu_kill callback to take down the CPUs in some
platform-specific manner.

The more difficult case is when you want to offline the secondary CPUs into
a pen and then boot them in the new kernel. I did get some of this working,
but there are outstanding issues with whether the pen should be at a fixed
location or not. If not, then we need a way to tell the new kernel where it
is, which may involve updating the DT blob...

Will